The (α, d) reaction on 12C and 13C and weak coupling configurations

Cross sections for the (α,d) reaction on 12C and 13C were measured at E sub(α) = 34.9 MeV in the range of excitation energies up to 11 MeV in 14N and up to 16 MeV in 15N. The angular distributions were compared to calculations with the zero-range distorted-wave Born approximation (DWBA) with the assumption of a deuteron-cluster transfer. On the basis of the assumption that the transferred two nucleons are weakly coupled to the target nuclei, very good correspondences between the transferred angular momenta and the strengths for the two-nucleon pairs were found for the residual nuclei 14N and 15N. Effects of the 0dsub(3/2) shell and a necessity for the tensor force are discussed in terms of the two-nucleon configurations dsub(3/2)psub(1/2) and (dsub(5/2))2, respectively. (author)